Fire-extinguisher composition



j UNITED STAT S PATENT HARRY S. MORK, or BnooxmNE, MASSACHUSETTS, ASSIGNOR, BY ME NE ASSIGNMENTS, To AMERICAN LA FRANCE FIRE ENGINE COMPANY, me, or ELMIRA, N W YORK, A

CORPORATION OF NEW YORK.

FIRE-EXTINGUIS HER COMPOSITION".

No Drawing.

' citizen of the United-States, residing at Brookline, county ofNorfolk, State of Massachusetts, have invented a certain new and useful F ire-Extinguisher Composition, of

I which thefollo'wing is a specification.

' charges and more particularly to the carbon- My invention relates to fire extinguisher ate solution from which carbon dioxid for expelling the l extinguishing medium is generated by reaction with a suitable acid. Alkali metal salts of carbonic acid, either in the form of bicarbonate or in the form of the normal carbonate have been commonly employed for such solutions, while sulfuric acid or hydrochloric acid has usually been employed as the acid charge. In order that the carbonate solution may always remain in a condition suitable for use even when exposed to low temperatures, it has been proposed to incorporate in the carbonate solution, an ingredient for lowering V. the freezing point thereof. Most of those ingredients which have been heretofore proposed for this purpose are subject to one disadvantage or another. In some instances, the addition agent tends to give rise to the formation of a precipitate of insoluble car- 'bonateor other salt or to retard the generacarbon dioxid gas;

tion or evolution of the or its eflect in small quantities has not been sufiiciently marked in depressing the freezing point.

The object of my invention is to produce a carbonate solution charge of the desired low freezing point which shall be free from the disadvantages above noted. At the same time, the invention seeks to avoid the use of ingredients which might lnvolve un due expense, or which would in any way interfere with the fire extinguishing qualities of the medium which is to be ejected from the apparatus.

The solutions embraced by my present invention, exhibit all the required qualities as a charge for fire-extinguishers and in addition to having the highly advantageous low freezing point, the capacity of the solution for giving off carbon dioxid gas when treated with acid, is greatly improved by .the presence of the ingredients for lowering the freezing point.

To clearly illustrate the principles of the art to understand and practise the same, I shall describe certain specific examples of the same.

The invention comprises a carbonate solution for 'fire extinguishers, in which a potassium salt of carbonic acid and glycerin are present as essential ingredients. This solution may be made up, for. example, as referred to in the following observations.

4.54 'gramsof potassium carbonate and 162 grams of glycerin when dissolved in 100 cubic centimeters of water, constitute a solution having a freezing point below 54 F. This solution at ordinary temperatures is quite fluid and in every way suitable for employment in a fire extinguisher. As the temperature is lowered, to about 44 F., the solution begins to become pasty. The

.from a comparison of a sample made up of evolution of carbon dioxid gas from the sothe simple solution of potassium carbonate in waterand one in which theglycerin is incorporated. Taking a test quantity of 15 cubic centimeters at 20 C. from a solution made up of 4.54 grams of potassium carbonate in 100 cubic centimeters of water, and treating this with l c. c. of sulfuric acid'of sufficient strength to neutralize two-thirds.

of. the carbonate present, the total gas evolution showed about 32% cubic centimeters at the end of the first minute, 3311- cubic centimeters at the end of the second minute, 34%

cubic centimeters at the end of the third minute, 35 cubic centimeters at the end of the fourth minute and no further increase up to the end of the fifth minute. The same test quantity at the same temperature from a solution made up of 4.54 grams of potassium carbonate and 162 grams of glycerin in 100 cubic centimeters of water, when treated with the same proportions of sulfuric acid showed a total gas evolution of about 39% cubic centimeters at the end of the first minute, 42% cubic centimeters at the end of the second minute, 43% cubic centimeters at the end of the third minute, 441; cubic centimeters at the end of the fourth minute, and no further increase up to the that case, the solution might comprise for example 6.6 grams of potassium bicarbonate and 149.8 grams of glycerin for each 100 c. c. of water. Such a solution would have a freezing point wcllbelow 70 F.

and have greater capacity to set free carbon dioxid than when the glycerin is not in-' cluded.

It will thus be seen that my invention provides not only for a very low freezing point of solution, but at the same time, considerably improves the capacity of the solution for developing Y carbon dioxid gas when treated With the acid in a fire extinguisher.

I claim: 7 r

A carbonate solution for fire extinguishers, comprising as essential ingredients normal potassium carbonate and glycerin, in substantially the proportions of 4.54 grams of potassium carbonate and l62grams of glycerin in 100 cubic centimeters of water.

HARRY S. MORK. 

